For half a century, Americans have whisked about the country on high-speed, but rather boring, interstate expressways. Romantics prefer older, two-lane highways that meander across the land. There, you can smell the new field corn and the Tuesday meatloaf special wafting from a local diner. You can gaze at vintage neon signs, crackling through the night, and listen to nostalgic tales of slower times gone by. So prepare your imagination for a visit to the noblest old, cross-country highway of them all.

It's U.S. Highway 66 -- or rather, the intact parts of it that the interstate highways passed by. First cobbled together in the 1920s, Route 66 began in downtown Chicago; wound across 4,000 kilometers, three time zones and eight states; and ended at Santa Monica, California's, Pacific Ocean Pier. Old 66 was the fast way west to Arizona's spectacular Grand Canyon. It was truckers' warm, fair-weather road; a military convoy route during World War Two; and then, in the 1950s and '60s, the hip and stylish road of Chevy convertibles, cheap gas, motor court motels, and "hippie" vans.

In those days, Route 66 was the "Main Street of America" -- the "Mother Road." John Steinbeck first used that term in his classic novel, The Grapes of Wrath. It told of sadder times along U.S. 66 in the 1930s, when Oklahoma "Okies" and other refugees fled terrible dust storms. "That 66 Highway, it's-a mighty hard," troubador Woody Guthrie sang back then. "All day you're hot, all night you freeze. But we gotta have work, so we're takin' a chance. From old Oklahoma to Los Angeleese."

In a later book, called Route 66: The Mother Road, historian Michael Wallis also wrote about those desperate times. "People had nowhere to go," he wrote. "They were tenant farmers. Their crops were gone. The dust literally took over the land. So they followed the scent of orange blossoms to the San Joaquin Valley in California. And fortunately, people along the way -- people of modest means -- did take them in. But in many instances, particularly on the borders of California or in Arizona at the inspection stations, these pilgrims, these migrants, these disenfranchised people were met with spittle and billy clubs. It was a tough journey. There was nothing romantic about it."

Nor were the times as carefree as Nat "King" Cole described them in 1946 in the song that became the unofficial anthem of the Mother Road. "If you ever plan to motor west," he sang, "travel my way, take the highway that's the best. Get your kicks on Route 66." At the time, many public accommodations were segregated by race. He would not have been welcome in most motels or cafes along the road. For white travelers, though, Route 66 bustled with one-of-a-kind gas stations and trading posts, biscuits-and-gravy coffee shops -- even conically shaped motels dressed up like Native American wigwams. But by the time Mr. Wallis published The Mother Road in 1990, decay had set in.

"So many towns were bypassed," he says, "that they had to figure out a way to stay alive. And some of them didn't. Some of them dried up. But 85 percent of the road is still there -- not only that old, varicose concrete and asphalt, but more importantly, the people along the road: the barbers, the fry cooks, the grease monkeys [auto mechanics], the cops, the farmers, the ranchers, the kids. They were the most important component of the road and still are."

They are people like Sue Preston. She is a former secretary who bought an old auto-repair shop in a dot of a town called Warwick, Oklahoma, and turned it into a Route 66 gift shop. "It's living history," she says of the road. "I think that's why it's so special. It's like a big family. If you live or work on Route 66, you just become part of a village. Lots of the people that had businesses in the '30s and the '40s, and they're still sitting in those businesses. And yes, they're not as prosperous any more. And they're a little rundown. But the people are still there, willing to talk about it, and willing to share their experiences. And visitors enjoy that."

Just down the road, near the little town of Arcadia, Oklahoma, you come around a bend and spy a big barn --- a round one, bright red with a green, egg-shaped cedar-shingle roof. It's said this is the most-photographed spot on all of Route 66.

At least it used to be back in the 1960s, when a television show about two men traveling Route 66 in a red convertible began a four-year run. Its theme song was a top-ten hit.

Over the years, much of Route 66 was plowed under to make way for five new interstate highways. The route was decommissioned as a federal highway in 1985. But those who love Old 66 put up orange-colored signs so tourists could find what remains.

These days along 66, you'll find kitschy art like the "Cadillac Ranch" outside Amarillo, Texas. A farmer half-buried ten Cadillac cars in the dirt there and invited passersby to spray-paint them any old way they pleased. People still stop with their spray cans and do just that, every day of the year.

Along Old 66 in Catoosa, Oklahoma, you can see a gigantic, restored blue whale that serves as a diving platform in a park. In Wilmington, Illinois, a fiberglass astronaut called the "Gemini Giant" looms outside the Launching Pad Drive-In restaurant. Elsewhere along the road, signs beckon you to the "Buckskin," "Wagon Wheel," "Blue Swallow," and other quaint motels. A few are still open, but many welcomed their last guest a generation ago.

On a lazy exploration of Old Route 66, you're apt to find lizards lolling in the sun, Model "T" Fords rusting outside dusty general stores, and old-timers just waiting for you to ask them about the glory days of the Mother Road.